1. Field
The present invention generally relates to methods and an apparatus for an atomic layer deposition lithography process, more specifically, to methods and an apparatus for utilizing an atomic layer deposition process along with a lithography process to form features/structures on a substrate surface in the semiconductor field.
2. Description of the Related Art
Integrated circuits have evolved into complex devices that can include millions of components (e.g., transistors, capacitors and resistors) on a single chip. The evolution of chip designs continually requires faster circuitry and greater circuit density. The demands for greater circuit density necessitate a reduction in the dimensions of the integrated circuit components.
As the dimensions of the integrated circuit components are reduced (e.g. to sub-micron dimensions), more elements are required to be put in a given area of a semiconductor integrated circuit. Accordingly, the lithography process has become more and more challenging to transfer even smaller features onto a substrate precisely and accurately without damage. In order to transfer precise and accurate features onto a substrate, a desired high resolution lithography process requires having a suitable light source that may provide a radiation at a desired wavelength range for exposure. Furthermore, the lithography process requires transferring features onto a photoresist layer with minimum structure and/or critical dimension alternation. Recently, an extreme ultraviolet (EUV) radiation source has been utilized to provide short exposure wavelengths so as to further reduce the minimum size printable on a substrate. However, at such small dimensions, the collapse or damage of the photoresist layer often occurs during the subsequent etching process, resulting in failure to successfully transfer structures onto a substrate surface.
In a conventional lithography process, some portions of a photoresist layer disposed on a substrate are exposed to incident radiation to undergo a chemical transformation. In a traditional positive tone exposure process, the exposed portion of the photoresist layer experiencing the chemical transformation is removed during the development process with an aqueous base solution. As the feature sizes formed on microelectronic device continue to shrink, the aqueous base solution developer may become problematic due to image collapse caused by the capillary forces and surface tension of water. Furthermore, solution based developers tend to leave undesired contaminates on the substrate after the development process, thereby adversely effecting the substrate cleanliness.
Therefore, there is a need for a method and an apparatus to control process defects for a lithography process with minimum structure damage so as to obtain a precise structure transfer onto a substrate surface with desired critical dimensions.